https://screenrant.com/big-bang-theory-bernadette-voice-origin-melissa-rauch/

Actor Melissa Rauch opens up to The Big Bang Theory co-star Mayim Bialik about why Bernadette Rostenkowski's voice is so high in the hit CBS sitcom.

Why Bernadette’s Voice Is So High In The Big Bang Theory (& Why It’s So Important) (https://screenrant.com/why-bernadettes-voice-is-so-high-in-the-big-bang-theory-why-its-so-important/)

Melissa Rauch's voice as Bernadette is one of the character's signature traits. But it's more important to The Big Bang Theory than just a gag.